Wire bonding processes and machines are used extensively as a practical and expedient method to bond wires to semiconductors. One example of the use of wire bonders in a semiconductor manufacturing process is for attaching a semiconductor dies directly to a circuit board substrate. The substrate includes numerous traces which terminate in pads that are positioned adjacent to the place where the die is to be mounted. The package itself includes numerous die pads that are to be electrically connected to the pads on the circuit board. A wire bonder is used to attach a conductive wire, typically having a diameter of between 0.00051 to 0.030 inches, to each die pad and then to the pads on the circuit board. The configuration of the die and the location of the pads require that the wire bonds be formed at varying X, Y and Z locations.
Automatic wire bonders have been developed which utilize stored position data for each wire bond. The wire bonders use the position data to control the bonding operation. The most common bonder uses a vertically or rotary (Z direction) displaceable wire bonding head along with a translatable (in the X, Y direction) semiconductor work table. Three high speed motors (one associated with each direction of movement) are used to position the semiconductor device and bonding tool at the appropriate locations.
Generally, the speed of a bonding machine is measured by the number of units that are completed per hour (or, alternatively, the number of wires bonded per hour.) One way to reduce the costs associated with the manufacture of a semiconductor product is to increase the speed of the bonding machine to increase the number of units produced per hour. The high speeds of current machines require the bonding head and the table to move at accelerations of between 10 and 12 g's. Increasing the accelerations above this range has been difficult due to the large mass and inertia that is involved in moving the various components of the bonding machines.
A need, therefore, exists for an improved wire bonding machine which provides high speed bonding.